Suspension device for thread guide lead of knitting machines



July 15, 1952 I V|TEK 2,603,074

SUSPENSION DEVICE FOR THREAD GUIDE LEAD OF KNITTING MACHINES T293 1 u f u M 0 Inve rdtor Marce Vil'ek.

- All'orneu Patented July 15, 1952 SUSPENSION DEVICE FOR GUIDE LEAD OF KNITTING MACHINES Marcel Vitek, Geneva, Switzerland 2 Application June 24, 1948, Serial No. 34,966

In Switzerland July 10, 1947 2 Claims.

In the knitting machine with warps, the thread junction with guides fixed to the suspension arms and permitting axial displacements of the thread guide bar, displacements which are necessary to the formation of the-meshes. These suspension devices are no longer capable of meeting the increased requirements which are wanted today. Indeed, it is now necessary to design knitting machines capable of more and more fast working; but, the higher the working speed, the greater is the increase of the extent of the vibrations generated by the oscillating movements of the thread guide and by their translation displacements before and behind the needles, so that practically a maximum speed is reached which is not suflicient for the present needs.

By closer examination of the thread guide suspension devices used on the known knitting machines, one notices immediately that they present two serious defects inherent in their design:

1. The thread guide bars are held only in a few points of their length, the number of these points and the distances between them being a function of the length of the knitting machine and of the number of arms provided by the suspension device. Now, these bars have compulsorily a transversal cross section of comparative much height with respect to their thickness andconsequently little resistance to bending in direction of the little inertia axis. It follows that the oscillating movement of the thread guides, imparted to the latter by their suspension device, generates vibrations of the free parts of the thread guide bar, the magnitudes of which increase rapidly with the frequency of the oscillatory movement, that is to say with the working speed. For certain frequencies, there may even take place resonance effects harmful to the proper running of the knitting machine;

2. The thread guide bars are guided by the oscillating arms themselves, so that the thread guides are situated at a comparatively long distance from their guiding point. Consequently, in order to obtain the required accuracy wanted in the longitudinal and transcendent position of the thread guides, so that they do not interfere with the needles, it is absolutely necessary to reckon with a very precise mounting of these guiding suspensions. In view of the strains to which are subjected the guiding surfaces of these arms, particularly when the thread guides translation displacements take place, it is clear that the working speed of the knitting machine cannot be increased beyond a certain maximum speed, without risk of inconsiderately reducing the life time of the thread guide suspension device.

The present invention relates to a suspension device for'the thread guide leads of a knitting machine, in which the said guides are rigidly fixed on thread guide bars mounted at the ends of oscillating arms by means of a guiding device permitting the axial displacements of the thread guides necessary to the formation of the meshes. This suspension device diifers from the known devices by the fact that the said device includes two elements sliding one into the other, of which one carries all the thread guide leads of a same warp, while the other connects rigidly between themselves all the oscillating arms carrying the said warp, each of these elements having cross sections of which the moments of inertia along the two principal axes are practically of the same order of magnitude.

The attached drawing shows diagrammatically and by way of example a form of embodiment of the suspension device.

The Fig. 1 is apart profile view with crosssection portion.

The Fig. 2 is a part front view of the guide bar fitted with its thread guide leads.

The Fig. 3 is a cross-sectionview of same along the line III-III of the Fig. l.

The Fig. 4 is a part cross-section view of an oscillating arm along the line IVIV of the Fig. 1.

In the embodiment shown on the drawing, the thread guides I, 2, are cast in lead blocks 3 fastened by means of screws on the thread guide bars 4, 5. The bar 4 carries the whole range of thread guides I, that is to say all the rear thread guides.

On the contrary, the bar 5 carries all the thread guides 2 which are the front row thread uides.

Each thread guide bar 4', or '5, is constituted by a profiled element having a resting surface 6 intended to receive the lead blocks 3, and constituting a part of a member I sliding into a guide 8 also constituted by a profiled element. This guide 8 connects rigidly all the oscillating arms 9, or ID, carrying the thread guides I ,or 2, belonging to a same thread guide row.

In the embodiment shown on the drawing, the thread guide bars are each a flange of a member 1 having generally a cross section shaped as an I, while the guides 8 have a transverse crosssection generally shaped as a U. On the ends of the wings of the U are fixed the guiding means ll arranged at a distance one from the other greater than the value of the total possible axial displacement of the thread guides.

The shoe of the I-section member 1 of the thread guide bar has recesses 12 of suflicient dimensions to permit the passage of the guiding organs II. a

By examining the attached drawing, one sees that the thread guide bars can be axially displaced, being each guided in a guide which connects rigidly all the oscillating arms of a same set of arms. This design presents the great advantage that all the thread guides of a same row are automatically lined up. Moreover, in order to avoid any permanent deformation of the guides in their parts situated between two adjoining oscillating arms, it is suificient to provide for these guides a section of dimensions and shape capable of imparting them a rigidity against bendin sufficient to withstand without deformations the stresses to which they are subjected when the knitting machine is working at high speed. 1

Now, owing to the pull exerted by the threads l3 passing through the'thread guides and to the oscillating movement of the arms, it is obvious that this guide must be capable of withstanding efforts exerted tangentially to the oscillatory movement as well as perpendicularly to the latter.

Consequently, it is advantageous to select for the guides a transverse section havin moments of inertia along its two main axes, approximately of the same value or at least of the same order of magnitude.

The same applies as regards the shape to select forthe transverse section of the member 1, since the latter is subjected to efforts of the same kind and of the same order of magnitude as the guides. g

One of the great advantages of the above described device is that it enables to bring as closely as possible the ends of the thread guides to their suspension and guidin so that any floating of the thread guide bar when the change of direction of the oscillatory movement is eliminated, while permitting an easy sliding in the guiding which does no longer require a very high degree of accuracy. 7

The setting in place and the removing of the parts 1 in or from their guides 8 is exceedingly quick and easy. Indeed, it is sufilcient to axially displace the part 1 so as to bring the recesses l2 in front of the guiding means I I, then to remove laterally the bar by letting the part 1 go through the guiding means I I thanks to the recesses l2.

The fact that two warp threads l3 must pass through the arm is not a drawback. In order to permit the passage of the two warp threads I3 it is suflicient to give to the arms ID, at the place of passage of the warp threads, the shape of a v as represented on the Fig. 4, so as to permit the axial displacements of the thread guide bars 1 without risk of hampering the warp in following these displacements. It is clear that all the faces against which the threads [3 can rub, that is to say the internal and external faces of the V, must be polished in order to avoid any catching of the threads and untimely breaking of same.

A form of embodiment of the object of the invention has been described herewith by way of example and in reference to the attached diagrammatic drawing. It goes without saying, however, that all the described organs and devices can be readily replaced by their equivalents.

Thus, the thread guide bars could have the general shape of a U sliding on guides having an I shape rigidly fixed to the ends of the oscillating arms.

One of the advantages of the described design is to permit fixing the guides 8 approximately in the transversal horizontal plane of the thread guide hook leads. This permits a guiding free from risks of jamming of the thread guide bar.

I claim:

1. A suspension device for a warp knitting machine, comprising, a plurality of thread guide leads, a member rigidly carrying the leads, a plurality of oscillating arms, a second member guiding the thread guide member in lengthwise movement necessary to the formation of the meshes and connecting rigidly all the oscillating arms carrying a warp, each of the said members presenting cross sections of which the moments of inertia about two main axes are practically of the same order of magnitude.

2. A device in accordance with claim 1 in which one of the members has a cross section of the general shape of an I while the other has a cross section of the general shape of a U.

MARCEL VITEK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,155,145 Mortonet al. Apr. 18, 1939 2,155,146 Morton et al. Apr. 18, 1939 

